Facultyhttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/469
Thu, 22 Feb 2018 04:56:30 GMT2018-02-22T04:56:30ZHabitat ecology and food and feeding of the herring bow crab Varuna litterata (Fabricius, 1798) of Cochin backwaters, Kerala, Indiahttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/4664
Habitat ecology and food and feeding of the herring bow crab Varuna litterata (Fabricius, 1798) of Cochin backwaters, Kerala, India
Aneykutty, Joseph; Deepthi, Gopi Nair; Lakshmi Devi, P
Habitat ecology and food and feeding of the herring bow crab, Varuna litterata of Cochin Backwaters, Kerala,
India were investigated for a period of one year (April 2011-March 2012). Among the 15 stations surveyed,
the crabs were found to occur only in 4 stations, which had a close proximity to the sea. Sediment analysis of
the stations revealed that the substratum of these stations is sandy in nature and is rich in organic carbon
content (0.79% to 1.07%). These estuarine crabs is euryhaline and are found to be distributed in areas with a
sandy substratum, higher organic carbon content and more tidal influx. The stomach contents analysis of crabs
examined showed that their diet included crustacean remains, plants, sand and debris, fishes, miscellaneous
group and unidentified matter. In adults and sub-adults, crustaceans formed the dominant food group, while in
juveniles, sand and debris formed the dominant group. From the present study, V. litterata was found to be a
predatory omnivore capable of ingesting both animal and plant tissues
Arthropods, 2013, 2(4): 172-188
Sun, 01 Dec 2013 00:00:00 GMThttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/46642013-12-01T00:00:00ZCurrent status and biodiversity modification in the coastal wetland ecosystems of India with objectives for its sustainable managementhttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/4454
Current status and biodiversity modification in the coastal wetland ecosystems of India with objectives for its sustainable management
Bijoy, Nandan S
The South West (S.W.) coast of India is blessed with a series of wetland systems popularly
referred to as backwaters covering a total area of 46128.94 ha. These backwaters are
internationally renowned for their aesthetic and scientific values including being a repository
for several species fish and shell fishes. This is more significant in that three wetlands
(Vembanad, Sasthamcotta and Ashtamudi) have recently been designated as Ramsar sites of
international importance. Thirty major backwaters forming the crux of the coastal wetlands
form an abode for over 200 resident or migratory fish and shellfish species. The fishing
activities in these water bodies provide the livelihood to about 200,000 fishers and also provide
full-time employment to over 50,000 fishermen. This paper describes the changes on the
environmental and biodiversity status of selected wetlands, during 1994-2005 period. The pH
was generally near neutral to alkaline in range. The salinity values indicated mixohaline
condition ranging from 5.20-32.38 ppt. in the 12 wetlands. The productivity values were
generally low in most of the wetlands during the study, where the gross production varied
from 0.22 gC/m3/day in Kadinamkulam to 1.10 gC/m3/day in the Kayamkulam. The diversity
of plankton and benthos was more during the pre-monsoon compared to the monsoon and
post-monsoon periods in most of the wetlands. The diversity of plankton and benthos was
more during the pre-monsoon compared to the monsoon and post-monsoon periods in most of
the wetlands. The average fish yield per ha. varied from 246 kg. in Valapattanam to 2747.3 kg.
in Azhikode wetland. Retting of coconut husk in most of the wetlands led to acidic pH
conditions with anoxia resulting in the production of high amounts of sulphide, coupled with
high carbon dioxide values leading to drastic reduction in the incidence and abundance of
plankton, benthic fauna and the fishery resources. The major fish species recorded from the
investigation were Etroplus suratensis, E. maculatus, Channa marulius, Labeo dussumieri, Puntius
sp. Lutianus argentimaculatus, Mystus sp., Tachysurus sp. and Hemiramphus sp. The majority of
these backwaters are highly stressed, especially during the pre monsoon period when the
retting activity is at its peak. The study has clearly reflected that a more restrained and cautious
approach is needed to manage and preserve the unique backwater ecosystems of South-west
India
Proceedings of the Conserv-Vision Conference, University of Waikato, 2-4 July 2007
Tue, 04 Nov 2008 00:00:00 GMThttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/44542008-11-04T00:00:00ZWater quality variation and nutrient characteristics of Kodungallur-Azhikode Estuary, Kerala, Indiahttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/4453
Water quality variation and nutrient characteristics of Kodungallur-Azhikode Estuary, Kerala, India
Bijoy, Nandan S; Sreedevi, O K; Jayachandran, P R
Present study focussed on the water quality status in relation to various anthropogenic activities in the Kodungallur-
Azhikode Estuary (KAE). Average depth of the estuary was 3.6 ± 0.2 m with maximum of 4.3 ± 0.4 m in the estuarine
mouth. Dissolved oxygen showed an average of 5.1±1 mg/l in the water column, whereas the highest BOD value was
noticed during monsoon period (3.1 ± 0.8 mg/l) which could be due to high organic enrichment in the water column. pH
displayed slightly alkaline condition in most of the stations and it varied from 7.2 ± 0.5 in Station 7 to 7.5 ± 0.5 in Station 1.
Salinity in the estuary displayed mixo-mesohaline nature with clear vertical stratification. High river discharge could have
resulted in nutrients and silt loading into the estuary, which makes a highly turbid water column particularly during the
monsoon period, which limits light penetration and subsequent primary productivity. Turbidity in the water column showed
an average of 20.2 ± 15.8 NTU. Estuary was nitrogen limited during post and pre monsoon periods. Nitrate-nitrogen content
in the estuarine water gave negative correlation with ammonia.
Indian Journal of Geo-Marine Sciences
Vol. 41 (2), April 2012, pp. 180-187
Sun, 01 Apr 2012 00:00:00 GMThttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/44532012-04-01T00:00:00ZSpecies diversity and community structure of ichthyofauna in the seagrass ecosystem of Minicoy Atoll, Lakshadweep, Indiahttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/4452
Species diversity and community structure of ichthyofauna in the seagrass ecosystem of Minicoy Atoll, Lakshadweep, India
Bijoy, Nandan S; Prabhakaran, M P; Pillai, N G K; Jayachandran, P R
Present study consists the species diversity, abundance and community structure of ichthyofauna in the seagrass meadow
of Minicoy Atoll, Lakshadweep Islands. Two hundred and three species of fishes were recorded during the study, from four
stations in the Atoll. They belonged to 2 classes, 11orders, 43 families and 93 genera. Six species belonged to the class
Chondreichthyes and 197 species to Osteichthyes. Family Pomacentridae showed maximum abundance of species (22%).
Station I, having close proximity to the coral reefs, observed the maximum number of families (37) and species (129) and
that with minimum number was in station II (23 families and 52 species). Bray-Curtis similarity plot showed a similarity
range of 22 to 52%, seasonally. Station I showed highest Shannon-Wiener diversity index (H’log2) (4.22) during August and
the lowest (2.91) during June. Stations I and III showed comparatively higher abundance and diversity of fishes. Variability
in seagrass habitat structure and the interaction with coral reefs influenced the species composition and diversity of fishes in
Minicoy Atoll. The findings of the present investigation can be used as baseline information for the fishery resource
management of the region
Indian Journal of Geo-Marine Sciences
Vol. 42(3), June 2013, pp. 349-359
Sat, 01 Jun 2013 00:00:00 GMThttps://dyuthi.cusat.ac.in:443/xmlui/handle/purl/44522013-06-01T00:00:00Z